The owner of a Swiss electronics firm yesterday admitted that a timer which prosecutors say was used in the bomb which blew up Pan Am flight 103 over Lockerbie could only have been supplied by his firm.

Edwin Bollier, co-owner of the Zurich-based company Mebo, admitted under questioning by prosecution counsel that fragments from a timer discovered by police investigating the bombing were part of the MST-13 timer made uniquely by Mebo.

Mr Bollier has waged a campaign in the press and on the internet denying that the detonator was supplied by his firm. He had claimed that a Florida-based firm had supplied identical detonators to the CIA, but yesterday he admitted that would not have been possible.

The Swiss businessman told the Scottish court in the Netherlands that he had supplied 20 of the sophisticated detonators to the Libyan secret services in Tripoli in 1985 in the hope of winning a contract from the military.

When he supplied the first batch of MST-13 timers he went with Libyan officials to the desert city of Sabha and watched as they were used in explosions. "I was present when two such timers were included in bomb cylinders," Mr Bollier told prosecutor Alan Turnbull QC. Earlier he told the court he had met one of the Libyan accused while he was in Tripoli. He said he believed Abdelbaset Ali Al Megrahi to be a major in the Libyan military, and that he might even be related to Colonel Gadafy.

Megrahi and Al Amin Khalifa Fhimah are accused of planting the bomb on the New York-bound jumbo, killing all 259 passengers on board and 11 locals in the Scottish borders town in December 1988.

The court heard that Mebo had done regular business with Libya, and in 1985 the company supplied 20 of its MTS-13 timers to the country in anticipation of a larger order, which never appeared.

Mr Bollier said the order for the prototypes was placed by one of two men, Said Rashid and Ezzadin Hinshiri. The timers were taken to the headquarters of the Libyan secret services before being tested in the desert trials.

During his dealings with Libya, Mr Bollier told the court, he came into contact with Megrahi. He said the Libyan accused had set up a business under the name of ABH at Mebo offices in Zurich.

Megrahi, 48, and Fhimah, 44, have denied charges of conspiracy to murder, murder, and breach of the 1982 Aviation Security Act.